Groundhogs do both. They are well-documented killing snakes that enter their territory, and there is credible evidence that they sometimes eat small snakes afterward. That said, groundhogs are overwhelmingly herbivorous, and snake-eating is rare opportunism rather than a meaningful part of their diet. The more common scenario is a groundhog defending its burrow from a snake and leaving the dead animal behind, which is probably why the “kill but don’t eat” impression persists.
What Groundhogs Actually Eat
Groundhogs (Marmota monax) are the largest members of the squirrel family in eastern North America, and their diet is roughly 90 percent plant material. They feed heavily on clover, alfalfa, dandelions, grasses, and garden vegetables, which is why they are the bane of backyard gardeners across the eastern United States and Canada. In late summer, they shift toward higher-calorie foods like berries, apples, and agricultural crops to build the fat reserves they need for winter hibernation.
The remaining fraction of their diet is animal protein, mostly in the form of insects, grubs, and the occasional snail. This puts groundhogs in the “opportunistic omnivore” category shared by many rodents. They do not hunt animal prey in any systematic way. Instead, they eat whatever small creatures they happen to encounter while foraging or digging. A grasshopper sitting on a clover patch gets eaten along with the clover. A grub uncovered during burrow excavation gets consumed. And sometimes, a small snake encountered in the wrong place at the wrong time meets the same fate.
Why Groundhogs and Snakes Cross Paths So Often
The interaction between groundhogs and snakes is not random. Groundhog burrows are elaborate underground systems that can stretch ten meters or more, with multiple chambers and exits. These tunnels maintain relatively stable temperatures year-round, which makes them attractive to cold-blooded animals. Research on pine snakes in the New Jersey Pine Barrens found that most natural hibernation sites used by those snakes were in abandoned burrows originally dug by large mammals.1PubMed. Fidelity of northern pine snakes (Pituophis m. melanoleucus) to natural and artificial hibernation sites in the New Jersey Pine Barrens Groundhog burrows are among the most common large-mammal burrows in the eastern U.S., so they frequently become snake real estate.
The overlap goes beyond abandoned dens. Active groundhog burrows attract rodents like mice and chipmunks, which shelter in unused side tunnels. Those smaller rodents, in turn, attract rat snakes, black racers, and even copperheads looking for a meal. So snakes often show up at groundhog burrows not because they are targeting the groundhog, but because the burrow ecosystem draws them in. The groundhog, however, does not make that distinction. A snake in or near the burrow is a threat, especially during the spring and early summer when pups are vulnerable.
How Groundhogs Kill Snakes
Groundhogs are surprisingly formidable fighters for animals best known for eating salad. An adult groundhog typically weighs between four and six kilograms and has powerful jaws designed for gnawing through roots and tough plant stems. Those same jaws can deliver a crushing bite to a snake. Groundhogs also have thick, loose skin and dense fur, which provides some protection against bites from smaller snakes. Their low center of gravity and stocky build make them difficult to coil around, and they are faster than they look over short distances.
When a groundhog encounters a snake near its burrow, the typical behavior is aggressive confrontation rather than retreat. Groundhogs have been observed charging snakes, stomping on them with their forepaws, and biting them repeatedly behind the head. This is defensive aggression, not predatory hunting. The groundhog’s goal is to neutralize a threat to itself and its young, and it usually succeeds against the non-venomous snake species it most commonly encounters. Black rat snakes, garter snakes, and black racers are the species most frequently reported in conflicts with groundhogs, and none of these pose a serious physical danger to a healthy adult groundhog.
After killing a snake, a groundhog may or may not eat part of it. Eyewitness accounts from homeowners, wildlife rehabilitators, and field biologists describe both outcomes. Some groundhogs drag the carcass away from the burrow entrance and ignore it. Others eat portions of it, particularly the softer midsection. The inconsistency probably reflects individual variation, hunger level, and the size of the snake. A groundhog that just spent ten minutes in a fight is not always in a feeding mood.
Venomous Snakes and the Question of Resistance
Most groundhog-snake encounters involve harmless species, but groundhogs do share habitat with copperheads and timber rattlesnakes in parts of their range. Whether groundhogs possess any physiological resistance to pit viper venom is not well studied in Marmota monax specifically, but research on closely related ground-dwelling squirrels is suggestive. California ground squirrels, which belong to the same broader family, have evolved measurable resistance to rattlesnake venom. Studies on the molecular interaction between rattlesnake venom and ground squirrel blood show that both venom potency and squirrel resistance vary geographically, reflecting a genuine arms race between predator and prey.2PubMed Central. Coevolution of venom function and venom resistance in a rattlesnake predator and its squirrel prey
Groundhogs are not the same animal as California ground squirrels, and the selective pressure driving venom resistance in those squirrels comes from being regular prey of rattlesnakes, which groundhogs largely are not. An adult groundhog is too big for most rattlesnakes to swallow. Still, the fact that venom resistance has evolved in multiple lineages of ground-dwelling sciurids suggests that some baseline tolerance may exist more broadly in the family. What we can say with confidence is that groundhogs typically avoid venomous snakes rather than picking fights with them. When confrontations do happen, the outcomes are less predictable than with non-venomous species, and a groundhog bitten by a copperhead or rattlesnake can certainly be injured or killed.
Defensive Killing Versus Predatory Feeding
The distinction between killing a snake and eating it matters because it reflects different motivations. Predatory behavior involves seeking out, stalking, and killing prey for the purpose of consumption. Defensive behavior involves neutralizing a perceived threat regardless of whether the animal is hungry. Almost everything we know about groundhog-snake interactions points to the defensive category. Groundhogs do not leave their burrows to hunt snakes. They do not track snakes by scent. They respond to snakes when snakes come to them.
That said, the line between defense and opportunistic feeding can blur. A groundhog that kills a garter snake and then eats it may have started fighting for defensive reasons but switched to feeding once the threat was over. This kind of opportunistic scavenging of a self-killed animal is common across the animal kingdom and does not really qualify as predation in any meaningful ecological sense. It is closer to how a house cat might eat a mouse it killed out of play or territorial instinct rather than hunger.
For the reader who just wants a straight answer: if you see a groundhog kill a snake in your yard, there is a reasonable chance it will eat some of it, but there is also a good chance it will not. Neither outcome is unusual.
What This Means for Your Yard
If you have groundhogs on your property, their presence probably reduces the number of snakes hanging around your yard, at least near the burrow entrances. Groundhogs are territorial animals that actively patrol the area around their dens, and snakes that wander too close are likely to be challenged. This does not mean a groundhog will rid your property of snakes entirely. Snakes that stay away from the burrow zone are generally left alone, and groundhogs are hibernating underground from roughly October through February, leaving the burrow complex undefended and available to snakes looking for winter shelter.
People sometimes ask whether they should encourage groundhogs to stay in their yard as a form of snake control. This is generally a bad trade. Groundhogs cause significant damage to gardens, foundations, and outbuildings through their digging. A single groundhog burrow system can undermine a shed foundation, damage a retaining wall, or create tripping hazards across a lawn. The modest snake-deterrent benefit they provide does not offset the structural and agricultural damage they cause. If you are worried about snakes, habitat modification and exclusion fencing are more effective and less destructive approaches.
Other Animals That Eat or Kill Snakes
Groundhogs are far from the only mammals that tangle with snakes. Several animals in the same size range are more committed snake predators. Opossums, for instance, carry a protein in their blood that neutralizes certain snake venoms, making them effective and relatively safe snake killers. Domestic cats kill large numbers of small snakes, though they rarely eat them. Foxes and coyotes eat snakes opportunistically, as do raccoons and skunks. Among birds, red-tailed hawks and great blue herons are regular snake predators in the same habitats where groundhogs live.
What sets groundhogs apart from these animals is that their snake killing is almost purely defensive. A fox that encounters a garter snake will often eat it without any defensive context. A hawk actively hunts snakes from the air. A groundhog only fights snakes that show up uninvited near its home. This distinction puts groundhog-snake interactions closer to the confrontations that happen between dogs and snakes than to genuine predator-prey relationships.
The Burrow Ecosystem After Groundhogs Leave
One of the more interesting aspects of groundhog-snake dynamics plays out after a groundhog abandons a burrow. Groundhog burrows can persist for years after the original occupant dies or relocates, and they become crucial habitat for a surprising range of wildlife. Rabbits, foxes, skunks, opossums, and various snake species all use abandoned groundhog burrows for shelter and hibernation. In regions with cold winters, these burrows can be the difference between survival and death for snakes that need frost-free refugia.
So there is an ecological irony at work. While a living groundhog is an active threat to snakes near its den, the infrastructure that groundhog leaves behind benefits snake populations for years. Herpetologists studying snake hibernation ecology have noted that the availability of suitable underground hibernation sites is a limiting factor for snake populations in many temperate regions. The extensive tunnel systems that groundhogs dig, sometimes reaching depths of a meter and a half, provide exactly the kind of deep, thermally stable refugia that snakes need to survive harsh winters. In this sense, groundhogs are both adversaries and inadvertent benefactors to local snake communities.
Why This Behavior Gets Misreported Online
Search for “groundhog eats snake” and you will find dramatic backyard videos, most of which show a groundhog killing a snake but cut off before you can tell whether it actually eats the thing. The internet has a strong appetite for unusual predator-prey footage, and a chunky herbivore attacking a snake is inherently surprising, so these clips get shared widely. The problem is that viewers often assume the killing implies eating, and the titles reinforce this. “Groundhog DESTROYS snake” becomes “Groundhog eats snake alive” in the next repost.
The reality, as covered above, is more nuanced. Groundhogs can eat snakes, sometimes do eat snakes, but mostly kill snakes out of defensive instinct and leave the carcass. The behavior is real but overstated in popular media. Wildlife biologists who study groundhogs do not list snakes or any other vertebrate as a regular component of their diet. If you read a source claiming that groundhogs “frequently” or “regularly” eat snakes, that source is extrapolating from occasional observations to a pattern that does not hold up across the species as a whole.
Similarly, claims that groundhogs are “immune” to snake venom are unsupported. While some related ground squirrel species have evolved measurable venom resistance, no published research has demonstrated the same in Marmota monax. A groundhog’s best defense against a venomous snake is the same as any other tough, fast animal of its size: avoid the fangs, attack the head, and hope the encounter is over quickly.
Seasonal Patterns in Groundhog-Snake Encounters
Most conflicts between groundhogs and snakes happen in late spring and early summer, for two overlapping reasons. First, groundhog pups are born in April or May and spend their first weeks underground, making the burrow a high-value asset that the mother will defend aggressively. Female groundhogs with young are measurably more aggressive than males or non-breeding females, and they are the ones most often observed attacking snakes near den entrances. Second, snakes are emerging from hibernation and becoming more active during the same period, increasing the odds of an encounter.
By late summer, groundhog pups have dispersed and adults are focused almost entirely on building fat reserves for hibernation. Their territorial aggression drops, and they are less likely to engage a snake that is not directly threatening them. By fall, groundhogs enter hibernation, their body temperature drops close to freezing, and they are completely inactive underground for months. During this period, snakes may actually move into the same burrow complex to hibernate, sometimes sharing the space with the torpid groundhog without any conflict at all. The relationship between these animals shifts with the calendar in ways that a single backyard video cannot capture.